Field of the Disclosure
The present disclosure is related to a display device having a touch sensor embedded therein and a method for driving the display device.
Discussion of the Related Art
Along with advancement of multimedia contents and in accordance with the needs for display devices capable of displaying the multimedia contents, flat panel display devices are nowadays being developed actively, which are characterized by a bigger display area, low cost, and high display quality (such as video expression, resolution, brightness, contrast, and color reproduction). These flat panel display devices are equipped with various kinds of input devices such as a keyboard, mouse, trackball, joystick, and digitizer as an interface for a user. However, to use the aforementioned input devices requires learning how to use them and incurs inconvenience as they occupy space for installation and operation thereof, thereby preventing high quality flat panel display products from coming to market. Therefore, there is a growing demand for an input device for display devices which is easy to use, simple, and capable of reducing malfunction. To meet the demand, a touch sensor has been proposed, which is capable of recognizing information input by a user touching the screen of a display device with his/her hand or pen or putting his/her hand or pen in close proximity to the screen.
A touch sensor used for a display device is often implemented by In-Cell method which embeds the touch sensor inside the display panel. A display device employing the in-cell touch method shares a touch electrode of the touch sensor and a common electrode of the display panel; and uses a display time and a touch sensing time interchangeably according to a time division scheme. Since the display panel and the touch sensor are driven by a time division scheme, operating time is not sufficiently secured. Moreover, as the operating time for the touch sensor is shortened, it is likely that touch sensitivity is degraded accordingly. In order to drive a touch sensor in a reliable manner, it is important to reduce a display time; however, if the display time is reduced, video display quality is degraded in return.